LSPECTRALGW: Difference between revisions
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{{TAGDEF|LSPECTRALGW|.FALSE. {{!}} .TRUE. | {{TAGDEF|LSPECTRALGW|.FALSE. {{!}} .TRUE.|.FALSE.}} | ||
Description: {{TAG|LSPECTRALGW}} specifies to use the spectral method for calculating the self-energy. | Description: {{TAG|LSPECTRALGW}} specifies to use the spectral method for calculating the self-energy. | ||
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Generally, {{TAG|LSPECTRALGW}} affects the compute time very little. QP energies also hardly | Generally, {{TAG|LSPECTRALGW}} affects the compute time very little. QP energies also hardly | ||
change when {{TAG|LSPECTRALGW}} is modified. | change when {{TAG|LSPECTRALGW}} is modified. | ||
However, {{TAG|LSPECTRALGW}} = .TRUE. is usually | However, {{TAG|LSPECTRALGW}} = .TRUE. is usually slightly more robust, | ||
and should be selected for molecules and other systems with flat bands. | and should be selected for molecules and other systems with flat dispersion-less bands. | ||
One the other hand, {{TAG|LSPECTRALGW}} = .TRUE. seems to converge slightly slower, | One the other hand, {{TAG|LSPECTRALGW}} = .TRUE. seems to converge slightly slower, | ||
as the complex shift {{TAG|CSHIFT}} is decreased. Set this flag, if the QP energies | as the complex shift {{TAG|CSHIFT}} is decreased. Set this flag, if the QP energies | ||
show erratic behavior, for instance, if QP energies or Z-factors are not in the expected | show erratic behavior, for instance, if QP energies or Z-factors are not in the expected | ||
range of values. | range of values (0.5<Z<0.9). | ||
== Related | == Related tags and articles == | ||
{{TAG|LSPECTRAL}} | {{TAG|LSPECTRAL}} | ||
{{sc|LSPECTRALGW|Examples|Examples that use this tag}} | |||
---- | ---- | ||
[[Category:INCAR]] [[Category:GW]] | [[Category:INCAR tag]][[Category:Many-body perturbation theory]][[Category:GW]] | ||
Latest revision as of 10:12, 19 July 2022
LSPECTRALGW = .FALSE. | .TRUE.
Default: LSPECTRALGW = .FALSE.
Description: LSPECTRALGW specifies to use the spectral method for calculating the self-energy.
If LSPECTRALGW = .TRUE. is set, the imaginary part of the self-energy is calculated from the imaginary part of screened potential by shifting the poles of by , where are the poles of the Green's function . Generally, LSPECTRALGW affects the compute time very little. QP energies also hardly change when LSPECTRALGW is modified. However, LSPECTRALGW = .TRUE. is usually slightly more robust, and should be selected for molecules and other systems with flat dispersion-less bands. One the other hand, LSPECTRALGW = .TRUE. seems to converge slightly slower, as the complex shift CSHIFT is decreased. Set this flag, if the QP energies show erratic behavior, for instance, if QP energies or Z-factors are not in the expected range of values (0.5<Z<0.9).
